Packing device



May 9, i939.

D. D. ROBERTSON ET AL PACKING DEi/ICE I Filed July 2, 1935 4 INVENTOR.e/zzaz .Dgezazz Patented May 9, 1939 UN'E'E STA'H'S ATENT orsi PACKINGDEVICE Application July 2,

4 Claims.

Our invention is a novel valve stem packing device and method ofassembling the same.

An object of our invention is to provide a packing arrangement adaptedto be manufactu'red and installed very economically.

Another object of our invention is to provide a packing device of verysimple character and one easily assembled.

A further object of our invention is to provide a novel tool forpreparing a valve stem guide for the reception of our novel packingdevice.

In accordance with our invention, the guide of the valve stem has agroove in its outer face near its end and a cage having legs Whose endsare seated in said groove is used to hold a ring of packing materialagainst the end of the valve stem guide. Such cage may be of the snapaction type. The groove for holding said cage is cut before the valveand stem are in place in the bore of the guide or while the valve stemis temporarily removed, and the cutting may be done by a tool comprisinga spindle-like rod, one end of which is adaptedto extend into the boreof the valve guide, a handle on the end of the rod, a cutter bar lyingin a plane including said rod and pivoted thereto so that it is capableof swinging toward and away from the rod to engage its transversecutting edge with the outside of the guide, and a nut threaded on theupper end of said rod and adapted to be turned toward the pivot of saidcutter to engage the end thereof on the opposite side of its pivot fromthe cutting edge to force the cutting edge against the outer face of thevalve stem guide. When the handle of the tool is now turned, the cuttermakes a groove in the guide in a plane at right angles to its bore.

The packing ring and cage may be assembled on the valve stem guideeither before or after the insertion of the valve-stem into thevalvestem guide, the stem inserted in the bore of the guide therefor,and the cage manipulated so that its edge engages into thegroove on theguide to hold the packing in place.

With the above mentioned and other objects in view, our inventionconsists of certain features of construction and certain process steps,as will be more fully .described and particularly pointed out in theappended claims, and we have illustrated in the accompanying drawingseveral devices embodying our` apparatus invention and adapted to beassembled in accordance with our process invention. In the drawing:

Figure l is a sectional view of a valve seat and a valve stem guidehaving a tool, in accordance 1935, Serial No. 29,448

(Cl. 12S- 188) with our invention, applied to the guide to cut a groovein the outer face thereof.

Figure 2 is a view similar to Figure l illustrating a tool adapted tocut a groove having a different form from the one shown in Figure 1.

Figure 3 is a fragmentary View on an enlarged scale of an end of thevalve stem guide shown in Figure l, having one form of our improvedpacking device applied thereto.

Figure 4 is a plan view on an enlarged scale of the cage member shown inFigure 3.

Figure 5 is a perspective View of the cage member shown in Figures 3 and4.

Figure 6 is a sectional view of the same valve seat and valve stem guideshown in Figure i but having the tool removed and the valve and stem inoperative position with two of our packn ing devices, including the cagemembers illustrated in Figures 4 and 5, applied to the stem guide.

Figure '7 is a plan view of a cage for use in our packing device whenthe groove on the guide is of the form illustrated in Figure 2, which isspecifically different from the groove form shown in Figure 1.

Figure 8 is a perspective View of the cage shown in Figure 7.

Figure 9 is a sectional view of the valve seat and valve stem guideillustrated in Figure 2 but having the tool removed and the valve andstem in operative position and having a modiiied form of packing device,including the cage member illustrated in Figures 7 and 8, appliedthereto.

The ordinary reciprocating valve, particularly of the type applied oncombustion engines, air compressors, and like structures has a stemwhich extends through a guide having a bore therein for receiving thestem. The guide surface in contact with the stem of the valve may be ona sleeve forced into an aperture in the bore of the cylinder casing ormay be integral with such casing, but in either case the end of suchguide projects so as to have a free end against which a packing isseated to seal the joint between the guide and stem. In most cases, thepacking material is pressed against the end of the guide by a cap whichis held in place by a coil spring. The use of such springs is a sourceof difculty, requiring a longer valve stem than would otherwise beneeded if the spring is on the outside of the cylinder body andcomplicating the assem bling and often requiring an additional spring tothat used for closing the valve. Furthermore, when the packing is in thepassage controlled by the valve, often the most convenient position inwhich to place it, the spring acting on the packing may become displacedor break and serve as a source of trouble difficult to discover; and thefollowing is a detailed description of several embodiments of ourinvention whereby the foregoing advantages may be obtained and thediihoulties avoided:

Referring to the drawing, I0 is a casting of a combustion engine, an aircompressor or analogous piece of apparatus, assumed to have a cylindertherein for the reception of a reciprocating piston. Casting I 0 has avalve seat I2 therein and, in axial alignment with said seat, we haveshown a valve stem guide I4 held in the opening I6 in the body I6 andhaving a driving t therewith, although the guide I4 may be integral withbody I6. The proper position of the sleeve guide I4 in body I0 isdetermined by a shoulder I8 on the member I4 which engages the outerface of the body I0, and the guide I4 has a bore 20 therein in alignmentwith the axis of the seat I2. As shown, both ends of the guide I4project from the body I0, the outer end I4-a being clear of the body andthe inner end I4--b projecting into the passage 22, which extendsthrough the port 24 surrounded by the seat I2. In order to prepare oneor both of the ends I4-a and I4--b of the body I4 for the application ofpacking means in accordance with our invention, we form in the outersurface or surfaces of such end or ends a groove or grooves 26--a and/or2li-b. While we do not limit ourselves to any particular means or methodfor forming the grooves 26-a and 2li-b, we have devised a tool 21, shownin working position in Figure 1, especially adapted for this purpose andcomprising a rod 28, having tip 3U adapted to enter the bore 28 andhaving a moderately close fit therewith. A collar 32 on rod 28determines the distance which the end of tip 36 may enter the bore 20.On the rod 28 is also a block 34 having a groove 36 therein in which ispivoted a cutter 38 of bar form which lies in a plane radial to the rod28 and has its pivot 46 in a plane transverse thereto, so that thecutting edge 42 can swing toward and away from the outer surface of theend I4B when the tool is in the position shown in Figure 1. On theopposite side of pivot 40 from the edge 42, the bar 38 has acomparatively long extension 38-a and the portion of the rod 28 outsideof the valve seat I2 has a thread 44 thereon whereby a nut 46 may beturned into engagement with the portion iS-a to force the cutting edge42 against the surface of the end Ill-b. If the rod 28 is now turned bymeans of the handle 48, it will be seen that the edge 42 will cut agroove 26-b in the outer surface of the guide I4, which is in a plane atright angles to the axis of bore 20. The shape of the groove 26-a or2li-l2` will be determined by the shape of the cutting edge 42, and thisis selected so that the grooves will cooperate properly with the cage tobe used upon the particular installation, as will presently more fullyappear.

After the groove 26--b has been cut, the tool 2`I is removed throughseat I2. The valve 50 may then be put in place so as to Cooperate withthe seat I2. Before placing the valve and valve-stem in operativeposition, however, the valve-stemguide I4 may have assembled thereon oneor two packing devices in accordance with our invention. In thearrangement illustrated in Figures l, 3, and 6, the packing ring 54 offelt, asbestos, or other suitable material, is held in place against theend surface of the end portion I4-b by means of a cage 55 of the formillustrated in Figures 4 and 5. The ring 54, Figure 3, may be on eitherend or both ends of the guide I4, but when such ring is to be used onthe inner end I4-b of guide I4, the ring 54 and cage 55 must beassembled on the stem 52 before such stem is inserted into the bore 20.As is clear from Figures 4 and 5, the cage 55 is a sheet metal stampinghaving a at head portion 56, a large portion of which is cut away toreduce the rigidity of the cage but which has at sectors 56-a adapted topress against and to hold the ring 54. EX- tending to one side of theplane of the head portion 56 are a plurality of legs 56-b, 56-5, whichare formed by cutting out of cage 55 sections 51, 5I, to provide greaterresilience. To increase the resilience also the cutouts in head 56 haveradial extensions 59, 59 which lie in the same radial planes as cutouts5'I between legs 58--b whereby adjacent sectors 56-a and adjacent legs56--b are connected by portions 6U of relatively small cross-sectionalarea and adapted to twist under torsion. Legs 56-b extend generally atright angles to head 56, but the inner portions of legs 56-b nearer head56 form portions of a conical surface which flares outwardly from theaxis through the center of the head 56. The outer portions of the legs56-5, however, bend inwardly toward said axis as indicated at 58, 58,and lie on a conical surface of slope much the same as that of grooves2li-a and 26-2). The ends of the legs 55--b are cut off the properlength and preferably at right angles to the inwardly extending portions58 so that portions 58 may lie in the V-shaped notches 26-a and 26-bwithout interference, the inner faces of portions 58 lying substantiallyparallel to and contacting with the outer face of the notch to hold thecage 55 in position as shown in Figures 3 and 6. Portions 58 projectinto the groove as shown when the cage 55 is in normal position and, inorder to assemble it in this position, the legs 56-b must be sprungoutwardly to permit the parts 58 to arrive at the groove '2B-a or 26-b.The cut out portions of cage 55 being so arranged, however, that thelegs 56-b and sectors 58-a are connected by relatively narrow strips ofmetal 68 permitting the legs 56-b to be sprung in the manner described,the cage 56 can be assembled in position to hold the packing ring 54 bymeans of a snap action. When in assembled position, the legs 56-b arestill somewhat sprung outwardly by the guide I4, so that their ends 58press the aring surface of groove 26-a or 26-b to which they are roughlyparallel and have a wedging action thereon to hold the cage firmly inplace. Also the stress on legs 56-b is transmitted to sectors 56--a sothat sectors 56-a are turned inwardly and press against the packing 54.

The casting l0', illustrated in Figure 2, is substantially the same ascasting ID shown in Figure l, but has therein a valve guide I4 intendedto receive only one of our valve stem packing devices instead of two asillustrated in Figures 1 and 6. The valve stem guide I4 of Figure 2,moreover, has a groove I4-c on its inner end which is of different formfrom that shown in Figure l. To cut such a groove, the tool 21 forcutting groove Il-c has a cutter portion 42 of diierent shape from thecutting edge 42. Otherwise, the tool 2'I, illustrated in Figure 2, isthe same as tool 21 of Figure 1. As shown, groove Ill--c has one side ina plane at right angles to the axis of guide I4.

The cage 55 of Figures 7 and 8 has, however, a somewhat different formfrom the cage 55 of Figures 4 and 5 to adapt it to better cooperate withgroove IIL-c. Since the groove lG-d while of V-shaped form, has one edgeat right angles to the axis of the guide i6 and the other edge at anangle thereto, the cage t', instead of being of a somewhatfrusto-conical shape such as cage 55, is of aA generally cylindricalform having legs provided with engaging tips 58 of inwardly taperingform complemental to the groove I 4-c. In Figure 9, We have illustrateda cage 56 arranged in position to hold a packing ring 54 in place toseal the joint between the valve stem 52 and the guide I4'. It will beunderstood that cage 56', when being assembled, must also be sprung orsnapped into position as shown in Figure 9.

It will be seen, however, that the resiliency of the cages employed byus is useful not only in snapping them into place, but also in snappingthem out of engagement with the grooves in the valve stem guide when itis desired to disassemble a given packing arrangement.

It Will be seen from the foregoing that our method or process ofassembling a packing device comprises cutting a groove in the valve stemguide in a plane at right angles to the axis of the guide, andassembling a packing and resilient cage on the stem, and xing them inplace against the end of the valve-stem guide by springing the cage sothat its edge seats in the groove.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and We,

therefore, desire the present embodiments to be `considered in allrespects as illustrative and nonrestrictive, reference being had to theappended claims rather than to the foregoing description to indicate thescope of the invention.

Having thus described the invention what is hereby claimed as new anddesired to be secured by Letters Patent, is:

1. A struck up cage for use in retaining a packing in position in useand adapted to be assembled by a snap action, such cage having asubstantially plane and partially cut out head` to decrease the rigidityof the cage, and spaced legs extending to one side of said head andconnected by relatively narrow portions of metal to increase theresilience of the cage, said legs terminating in inturned grippingportions.

2. A cage for retaining packing in operative position and comprisinglegs extending generally at right angles to a head portion and havingrelatively narrow connecting portions between said legs to increase theresiliency of the Cage, said legs having inturned end portions providedwith inclined surfaces adapted to exert a Wedging action on a retaininggroove.

3. A struck up cage for retaining a packing in operative position andcomprising a substantially plane head portion cut out to providesectors, spaced legs fixed to said head and extending in one directiontherefrom, said legs flaring outwardly from said head and then inwardlytoward the axis thereof and having end portions adapted to engage oneface of a V-shaped groove and exert Wedging action thereon.

4. In an internal combustion engine having a combustion chamber and apassage for oil-bearing gas, a valve controlling the movementV of saidgas between the chamber and passage, a valve stem for the valve, a guidemounting the stem, said guide and stem being positioned in relativelyclose proximity to the combustion chamber and gas passage whereby theguide and stem are subject to high temperature and oil during operationof the engine, a packing for the stem comprising a generally annularsealing member surrounding the stem and engaging an end of the guide,and a metallic cage having a portion holding the sealing member againstsaid end of the guide, another portion engaged with the guide, and anintermediate portion connecting the two named portions, saidintermediate portion being comparatively inextensible.

DEIMAR D. ROBERTSON. GEORGE L. BRIGGS.

